1. Field of the Invention
This invention relates generally to flow valves and more particularly to a valve for use in a fire alarm system or fire sprinkler system.
2. Description of Related Art
The following art defines the present state of this field:
Smith, U.S. Pat. No. 2,076,600 describes a device of the class described comprising a body having a through flow passage, a pivotally mounted vane normally extending transversely of the line of flow through said passage, said vane being swingable under the force of fluid traversing said passage, there being an orifice communicating with said passage, a movable valve element controlling said orifice, cam means rocked as a result of swinging of said vane, and follower means engaging said cam means and connected to said valve element for controlling the latter in dependence upon the position of said vane.
Jackson et al., U.S. Pat. No. 2,197,473 describes a flow indicator in combination, a fluid conduit having an aperture therein, a housing providing a fluid chamber, a tubular fitting adapted to be secured to the side of the conduit adjacent said aperature for connecting said housing and conduit and providing communication between the housing chamber and interior of the conduit, said fitting provided with a valve seat thereon, a valve arranged to cooperate with said valve seat, and impeller arranged within the conduit connecting means between said impeller and valve for actuating the valve upon actuation of the said impeller by the fluid within the conduit, said housing provided with and outlet from said chamber, a manually operated valve for regulating the rate of flow through said outlet, a circuit controller arranged without said chamber, and means operative by fluid within the chamber for controlling said circuit breaker.
Hudson, U.S. Pat. No. 3,284,788 describes a system for monitoring the rate of flow of a substance, said system comprising first and second circuits, each of said first and second circuits comprising first and second clamp circuits and first and second timer circuits, respectively, a two-position switch having a movable contact, means to apply a source of voltage to said movable contact, means cooperatively engaged with said movable contact to actuate said switch from one of two positions to the other of said two positions at a frequency whose period is a function of the rate of flow of said substance, means connecting said first circuit to said switch to energize said first clamp circuit when said switch is in one of said two positions thereof, means connecting said second circuit to said switch to energize said second clamp circuit when said switch is in the other of said two positions thereof, means including a source of voltage to energize said first or said second timer circuit when said first or said second clamp circuit, respectively, is de-energized, said first and said second timer circuits comprising means to produce and output signal when energized for a predetermined period of time, and means connecting said first and said second timer circuits to said output means to apply said output signal thereto.
Reaves, U.S. Pat. No. 3,688,645 describes a valve control apparatus including a housing having a shaft member rotatably mounted therein. One end of the shaft member is connected to a valve stem of a valve to be controlled. The shaft member has a radially projecting vane fixed thereto which is rotatable through a predetermined arc within the housing. A unitary seal is provided to encircle the shaft member above and below the vane and to surround the periphery of the vane. A groove is formed in the periphery of the vane to support the seal. Fluid is selectively introduced into the housing to rotate the vane and shaft member in a desired direction. The unitary seal provides a continuous sealing surface which prevents fluid leakage from one side of the vane to the other and prevents fluid leakage from the inside to the outside of the housing along the shaft member.
Johnson, U.S. Pat. No. 4,197,809 describes a flow responsive device for use in a fluid flow system to establish a signal when a predetermined flow rate is attained within a flow conduit. The device is adapted for connection to a flow conduit and has a target vane adapted for insertion within the flow conduit for movement in response to predetermined flow to open internal valve means against the bias force of a compression spring and control pressure within a pressure chamber. In operation, the control pressure is maintained at a higher pressure than the fluid pressure within the flow conduit so that after initial opening of the valve means, the control pressure drops and the valve means undergoes fast-action movement to its fully open condition. The flow rate at which the valve means closes is less than the flow rate at which the valve means opens so that hunting of the valve means during operation is prevented. The pressure chamber may be connected to a control line having a flow restrictor therein so that when the valve means is opened, a pressure drop across the flow restrictor establishes a signal which may be employed to control external equipment.
McHugh, U.S. Pat. No. 4,991,655 describes an alarm valve and a backflow preventer providing a check valve and an alarm valve with a passageway provided between the check valve and the alarm valve preferably having a relief valve which selectively drains the passageway in response to the pressure in the main conduit upstream of the check valve. An alarm is sounded when the alarm valve is open. An impeller flow sensor may be provided in the backflow prevention device.
Leete, U.S. Pat. No. 5,101,862 describes an oscillatory rotary actuator providing for controlling an adjustable valve. The actuator comprises a freely rotating, cylindrical housing with concentric inner and outer walls about its center. The housing has at least one depending vane, which functions as a rotary piston, that is radially disposed between the inner and outer walls. The rotary actuator further comprises an annular chamber casing which has two concentric walls that are designed to mate between the inner and outer walls of the housing member to receive the depending vane(s) between the concentric walls of the chamber casing. At least one radially extending chamber wall is interposed and attached to the concentric walls of the chamber casing. When the housing member is fitted over or receives the annular chamber casing, the housing, chamber casing and chamber wall collectively form at least one rotary chamber for the arcuate movement of the depending vane, or rotary piston, therein. A valve control system is also provided for the operation of an adjustable valve for controlling the flow of fluid therethrough from a control module located at a distance from the valve. The valve can be operated as a function of a desired valve position utilizing actuator position feedback sensing; desired fluid pressure utilizing pressure feedback sensing; or desired fluid flow rate utilizing flow feedback sensing. The adjustable valve is preferably one that has a quarter turn from the open to the close position, such as a ball valve or butterfly valve.
McHugh, U.S. Pat. No. 5,588,462 describes a valve and sensor arrangement including a valve which has a valve member. A sensor such as a sensor for detecting a flow of water through the valve is provided within the valve member and is preferably perpendicular to a turning axis of the valve member. The sensor is preferably a flow sensor which is rotated by flow through the valve and the sensor arrangement may be provided in a valve of general utility.
Miller, WO99/56092 describes a flow sensor using induction pickup and having an improved paddle wheel type impeller within an impeller housing having a concave opening defining a protective skirt area for shielding a portion of the paddle wheel and a stem of the paddle wheel with a varying thickness for reducing cavitational backflow and therefore achieving a precise measurement of the fluid flow velocity and a high turndown ratio.
The prior art teaches the use of flow valves of various types, but does not teach the present use of a cam surface for selecting a relationship between a fluid energized paddle and an opening of a flow aperture.
The present invention teaches certain benefits in construction and use, which give rise to the objectives described below.
A hydraulic flow valve apparatus has a valve body providing a cavity with an eccentric sidewall. The sidewall terminates with a conical bottom surface defining a flow aperture at its apex. A sealing shaft is fitted within the cavity and is enabled for lateral movement due to the eccentric sidewall. The sealing shaft provides at one end, a rubber seat which normally seals the flow aperture, and at the other end, it provides a planar surface set at an off-normal angle. A fluid actuated vane extends away from the frontal surface of the valve body and is pivotally engaged with the planar surface of the sealing shaft so as to move the sealing shaft laterally, which action then uncovers the aperture when the vane is forced out of a selected preliminary alignment with the sealing shaft. A cam engaged with the vane is used to select a desired relationship between the motion of the vane and the motion of the sealing shaft. By selecting a particular cam shape, the vane""s motion is transmitted to the sealing shaft in a transfer curve of one""s choice. The cam may be replaced with an alternate cam to change the transfer function. The application of the present invention is for fire sprinkler systems. In such systems the vane is immersed in a water supply pipe that is normally filled. When a fire sprinkler ruptures, water flow starts in the water supply pipe and this moves the vane and uncovers the aperture. Water flows through the aperture and thereby provides a means for generating a fire alarm signal. False triggering of such alarms is of importance. Motion of the ground by natural or man-made causes, pressure testing of the fire control system, developed water leaks, and many other causes can result in false alarms. The present invention is a means for assuring that certain types and durations of motion of the vane can occur without triggering a false alarm, while assuring that an alarm will occur when significant and sustained water flow occurs.
A primary objective of the present invention is to provide an apparatus and method of use of such apparatus that provides advantages not taught by the prior art.
An important objective is to provide such an invention capable of opening a valve in accordance with a highly specific and selectable fluid flow characteristic.
A further objective is to provide such an invention capable of being easily adapted to alternate valve flow characteristics.
A general objective is to provide such an invention capable of simple adaptation to various systems where false water flow alarms are caused by significantly different circumstances.
Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.